So if you create a new user using mass-assignment, it may be too easy to become an administrator.

-Note that this vulnerability is not restricted to database columns. Any setter method, unless explicitly protected, is accessible via the <tt>attributes=</tt> method. In fact, this vulnerability is extended even further with the introduction of nested mass assignment (and nested object forms) in Rails 2.3+. The +accepts_nested_attributes_for+ declaration provides us the ability to extend mass assignment to model associations (+has_many+, +has_one+, +has_and_belongs_to_many+). For example:

+Note that this vulnerability is not restricted to database columns. Any setter method, unless explicitly protected, is accessible via the <tt>attributes=</tt> method. In fact, this vulnerability is extended even further with the introduction of nested mass assignment (and nested object forms) in Rails 2.3==+==. The +accepts_nested_attributes_for+ declaration provides us the ability to extend mass assignment to model associations (+has_many+, +has_one+, +has_and_belongs_to_many+). For example: